СЕРОВОДОРОД КАК ТРЕТЬЯ ЭССЕНЦИАЛЬНАЯ ГАЗОВАЯ МОЛЕКУЛА ЖИВЫХ ТКАНЕЙ

The data of foreign studies over the last 15 years devoted to endogenous synthesis and biological role of hydrogen sulfide in micromolar quantities which complemented the already two well-known gas transmitters — OH and NO are presented in this review. Despite the short period since the physiological properties of hydrogen sulfide were opened (about 20 years) it was found that this gas transmitter plays a key role in the regulation of nerve (neural signal transmission), cardiovascular (relaxation of smooth muscles), immune (anti-inflammatory and cytoprotective agent) sensory, gastrointestinal (output of insulin) systems and in the metabolism of various organs. Currently the role of H2S in the pathogenesis of different diseases, neurodegenerative diseases, diabetes, heart failure) is being studying. The developments of drugs that act as either exogenous donors H2S or blockers of the biosynthesis of H2S are promising. With consideration the fact that H2S is a representative of non-synaptic way of intercellular communication based on diffusion of molecules of inorganic compounds in the intercellular space in all directions and effect on distant from their place of formation non- synaptic receptors it is suggested to use exogenous H2S in strict proportion for the treatment of a number of human diseases. Представлены данные зарубежных исследователей за последние 15 лет, посвященные эндогенному биосинтезу и биологической роли сероводорода в микромолярных количествах, который дополнил уже два известных газотрансмиттера — ОН и NO. Несмотря на незначительный период со дня открытия физиологических свойств сероводорода (около 20 лет), установлено, что этот газотрансмиттер играет ключевую роль в регуляции нервной (нейронная передача сигнала), сердечно-сосудистой (расслабление гладких мышц), иммунной (противовоспалительный и цитопротекторный агент) сенсорной, желудочно-кишечной (выход инсулина) системы, а также в метаболизме различных органов. В настоящее время ведется изучение роли H2S в патогенезе различных заболеваний (нейродегенеративные болезни, сахарный диабет, сердечная недостаточность). Перспективными являются разработки по созданию препаратов, которые выступают либо в качестве экзогенных доноров H2S, либо в роли блокаторов биосинтеза H2S. С учетом того факта, что H2S является представителем несинаптического способа межклеточной коммуникации, основанного на диффузии молекул неорганических соединений по межклеточному пространству во всех направлениях и действии на отдаленные от их места образования несинаптические рецепторы, предлагается строго дозированно использовать и экзогенный H2S для лечения ряда заболеваний человека.

Effect of pressure on the characteristics of Schottky barrier diodes made of overcompensated semiconductor

We studied the effect of uniform compression on characteristics of Au–n-Si Schottky barrier diodes made of overcompensated semiconductor. It is shown that overcompensation is caused by formation of structural defects owing to thermal treatment of the initial silicon wafers

Effect of pressure on the properties of Al-SiO₂-n-Si<Ni> structures

We investigated the effect of hydrostatic pressure on relaxation characteristics of the three-layer Al-SiO₂-n-Si structures. It was found that 20 min exposure to a pressure of 8 kbars results in reduction of the integral density of surface states, while exerting no influence on the generation centers in the bulk

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters

Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary

This paper constructs the reduction of heterotic $M$-theory in eleven dimensions to a supergravity model on a manifold with boundary in five dimensions using a Calabi-Yau three-fold. New results are presented for the boundary terms in the action and for the boundary conditions on the bulk fields. Some general features of dualisation on a manifold with boundary are used to explain the origin of some topological terms in the action. The effect of gaugino condensation on the fermion boundary conditions leads to a `twist' in the chirality of the gravitino which can provide an uplifting mechanism in the vacuum energy to cancel the cosmological constant after moduli stabilisation.Comment: 16 pages, RevTe

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review